Impact of an Ivermectin Mass Drug Administration on Scabies Prevalence in a Remote Australian Aboriginal Community Academic Article uri icon

abstract

  • BACKGROUND:Scabies is endemic in many Aboriginal and Torres Strait Islander communities, with 69% of infants infected in the first year of life. We report the outcomes against scabies of two oral ivermectin mass drug administrations (MDAs) delivered 12 months apart in a remote Australian Aboriginal community. METHODS:Utilizing a before and after study design, we measured scabies prevalence through population census with sequential MDAs at baseline and month 12. Surveys at months 6 and 18 determined disease acquisition and treatment failures. Scabies infestations were diagnosed clinically with additional laboratory investigations for crusted scabies. Non-pregnant participants weighing ≥15 kg were administered a single 200 μg/kg ivermectin dose, repeated after 2-3 weeks if scabies was diagnosed, others followed a standard alternative algorithm. PRINCIPAL FINDINGS:We saw >1000 participants at each population census. Scabies prevalence fell from 4% at baseline to 1% at month 6. Prevalence rose to 9% at month 12 amongst the baseline cohort in association with an identified exposure to a presumptive crusted scabies case with a higher prevalence of 14% amongst new entries to the cohort. At month 18, scabies prevalence fell to 2%. Scabies acquisitions six months after each MDA were 1% and 2% whilst treatment failures were 6% and 5% respectively. CONCLUSION:Scabies prevalence reduced in the six months after each MDA with a low risk of acquisition (1-2%). However, in a setting where living conditions are conducive to high scabies transmissibility, exposure to presumptive crusted scabies and population mobility, a sustained reduction in prevalence was not achieved. CLINICAL TRIAL REGISTRATION:Australian New Zealand Clinical Trial Register (ACTRN-12609000654257).

authors

  • Kearns, TM
  • Speare, R
  • Cheng, AC
  • McCarthy, J
  • Carapetis, JR
  • Holt, DC
  • Currie, BJ
  • Page, W
  • Shield, J
  • Gundjirryirr, R
  • Bundhala, L
  • Mulholland, E
  • Chatfield, M
  • Andrews, RM

publication date

  • October 30, 2015